In cold climates where temperatures below 0.degree. C. are encountered for weeks or months at a time, it is necessary to provide protection for fresh-water pipes from a water main so that they do not freeze. There are numerous methods presently utilized, however they are all either complicated or expensive to operate.
One method utilizes two pipes from a water main with a circulating pump for continuously circulating water through the pipes and the unit water system. This system requires the additional cost of installing a second pipe and a pump and the pipe may still freeze if there is a power failure or if the pump fails.
Another method utilized is to heat trace the entire length of the service pipe from the water main with an electrical heating tape, and then insulating the water pipes. Here again there is an inherent high installation cost and if there is a break in the electrical heating tape or if there is a power supply failure, there is a great likelihood that water in the service pipe will freeze.
There is therefore a great need for a system for use in northern climates to prevent water in a service pipe to a residence or the like from freezing which is not dependent upon a power supply so that when the power supply fails the system will still operate to prevent water from freezing in the service pipe.